biotinylation of proteins

Why would someone want to biotinylate a protein? How can the mechanisms of protein conversion to a mutated form be studied with a biotinylated protein? What else can be studied with a biotinylated protein?
thanks!!!

We can help, but won't unless you actually demonstrate that you have put some effort into answering the questions yourself... Think about what biotinylation allows us to do with a protein. i.e. what is special about biotin?